Highest temperature in Sao Paulo on June 30?

Platform comparison

Market context

The underlying event is the peak daytime temperature recorded at São Paulo–Guarulhos International Airport on 30 June 2026, measured in degrees Celsius. Historical patterns for São Paulo in June show mild, cool conditions with average highs of 23°C and lows of 13°C, often accompanied by breezy winds and high humidity [1]. The coldest month is July, reinforcing that late June remains firmly within the cool season, with typical highs rarely exceeding 25°C [3]. Even the hottest December record of 35.9°C and the November peak of 38.5°C are seasonal outliers far removed from June’s climate profile [4][6]. Given this consistent thermal baseline, a 0% implied probability for any temperature above the standard June range aligns with decades of observational data, showing no meaningful divergence from analyst consensus on this contract.

Traders should monitor the daily weather forecast schedules issued by Brazil’s National Meteorological Institute (INMET) for any anomalous heatwave warnings ahead of 30 June, though such events are statistically negligible in this season. Recent historical data from June 2026 shows a maximum of 26°C on 22 June, confirming the absence of extreme heat spikes [2]. No major atmospheric announcements or climate dependencies currently suggest a deviation from the norm, and the settlement window relies solely on Wunderground’s verified daily maximum for the airport station. With no credible catalysts for a temperature surge, the cross-platform odds remain stable, and sportsbook lines for similar weather contracts in São Paulo consistently reflect June’s cool reality, leaving no room for speculative divergence.

Sources: 1 · 2 · 3 · 4 · 5

Methodology

We track Highest temperature in Sao Paulo on June 30? across the five venues with material prediction-market liquidity. The probability shown is the live Polymarket mid; the comparison rows summarise how each venue treats the underlying contract — fees, KYC thresholds, settlement currency, deposit options. The highlighted row marks the cheapest route into Polymarket's order book.

Resolution & payout

Settlement runs on-chain. Polymarket's contract logic separates YES and NO shares as conditional tokens; at resolution the winning share lifts to $1.00 and the losing one to $0. The outcome input comes from the UMA Optimistic Oracle, which secures against bad resolution with a bond + dispute window.

Once finalised, the smart contract pays USDC to the holders' wallets within minutes — no withdrawal fees beyond Polygon network gas. Kalshi settles in USD via CFTC clearance, Betfair in account currency net of commission, Manifold in play-money mana with no cash-out.

FAQ

Is this market available outside the US?

Polymarket itself is geo-blocked in the US/UK/EU. Always check the legal status of prediction markets in your jurisdiction before trading.

How does resolution work?

Through the UMA Optimistic Oracle on Polygon: a proposer submits the outcome, a two-hour challenge window opens, and USDC payouts settle automatically once the result is final.

What does Polymarket cost to trade?

Polymarket itself charges 0% — the only cost is the Polygon network fee, typically under $0.01 per transaction. Off-chain venues like Kalshi or Betfair charge 2-7% commission.

How fast are USDC deposits?

Polygon credits deposits after 12 confirmations — usually under 30 seconds. Withdrawals follow the same path and land back in your wallet within minutes.

Do I need to KYC for this market?

On Polymarket directly, no — it's wallet-based. Intermediary brokers like Best Prediction Markets trigger KYC only above $1,500 of lifetime trading volume; under that you trade pseudonymously with a single wallet address.